Top Speed Estimator

Estimate theoretical top speed from power, drag coefficient, frontal area and weight.

How it works

1

Enter power & aero

Crank power, drag coefficient (Cd) and frontal area in m² (typical car ≈ 2.0–2.3 m²).

2

Account for losses

Drivetrain loss reduces the power reaching the wheels.

3

Read top speed

At top speed all wheel power goes into pushing air aside — we solve for that balance.

Frequently asked questions

How is top speed calculated from power?

At top speed, wheel power equals aerodynamic drag power: P = ½·ρ·Cd·A·v³. We solve for v using air density ρ ≈ 1.225 kg/m³. It is an aerodynamic-limited estimate that ignores gearing and rolling resistance, so real top speed may be a little lower.

What Cd and frontal area should I use?

Typical Cd: 0.28–0.35 for saloons, 0.32–0.40 for SUVs. Frontal area is roughly 2.0–2.3 m² for cars, more for SUVs. Manufacturer figures give the best result.

Is gearing included?

No — this is the aerodynamic limit. If the car is gear-limited (hits the rev limiter before this speed), real top speed will be lower.

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